SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fd7afc665d32ad33f3faaaf989ee16fe167b14d5d563242ff47290343331b5e' 
  AND token = '1j74X/b9njEhpIUi8vjSHZSoh4NVNevKdSnly0kvdvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}